It is known in the art to bond carbonaceous shapes together to form assemblies such as refractory linings in metallurgical equipment and cupolas in blast furnaces. These shapes have been bonded with a carbonaceous cement containing, for example, carbonaceous particles, a furan derivative, and a thermosetting phenolic resin. An example of such a cement is disclosed in U.S. Pat. No. 3,441,529, to L. W. Tyler.
Machined graphite shapes are used in the aerospace industry as molds, and the like, for the production of composite structures. These graphite shapes are often very large. For example, some of the graphite molds are large enough to form an entire wing structure. Because of the size of these graphite molds, it is necessary to form these structures from a cement bonded assembly of smaller graphite shapes. A problem with these assemblies, is that the strength of the joints between the individual graphite shapes is often insufficient, resulting in early failure of the mold. The curing temperatures for high-performance composite materials used in the aerospace industry are often as high as 450.degree. C. At these high curing temperatures, conventional carbonaceous cements degrade and their bond strength is, therefore, seriously reduced. As a result, the strength of the joints at curing temperatures is often less than a fourth of the strength of the graphite material used to fabricate the assemblies.